Sealing and/or cutting instrument

ABSTRACT

A sealing and/or cutting instrument having a thermally active surface or element which may be used to seal and then cut tissue, ducts, vessels, etc., apart. The instrument may include a thermally active surface or element comprised of a conductor covered with a ferromagnetic material. The instrument may contact tissue with one or more surfaces comprised of a non-stick material. A sensor in communication with the instrument may be used to monitor a therapeutic procedure and signal when sealing and/or cutting of a tissue is complete.

PRIORITY

The present application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/534,047, filed Sep. 13, 2011 and U.S.Provisional Patent Application Ser. No. 61/534,322, filed Sep. 13, 2011,which are incorporated herein by reference in their entirety.

THE FIELD OF THE INVENTION

The present invention relates to surgical instruments. Morespecifically, the present invention relates to tissue cutting andsealing instruments.

BACKGROUND

Human and animal bodies contain a number of ducts for moving fluids andmaterial, such as blood vessels for carrying blood, the digestive tractfor transporting and processing food, reproductive ducts fortransporting reproductive fluids and gastric ducts for passing bile andother fluids. (As used herein duct is used broadly to encompass ducts,vessels, tubes and other ducts in a human or animal body. Bodies alsoinclude various tissues for performing functions necessary to maintainthe body. During surgery, these ducts or tissues may get in the way ofthe surgical procedure or may need to be cut for a variety of reasons.Additionally, these ducts or tissues may need to be closed andseparated. In some cases, these ducts or tissues are the reason or partof the reason for surgery, such as tubal ligation, gall bladder removal,or resecting tissue of an organ, etc. Thus, a surgeon may clamp, blockand/or cut ducts or tissue(s) in a variety of situations.

Separating ducts or sealing and cutting tissue can take time and requiremultiple instruments. Sometimes multiple instruments may be needed foreach step during a surgical procedure. In the case of blood, if thesurgeon does not adequately clamp, block and cut and tie-off orotherwise seal the blood vessels or other ducts or tissue, blood orother body fluids may leak. This may cause the unfortunate effect ofobfuscating the surgical area and create other concerns such as causingblood coagulation and build-up on a surgical instrument. Moreimportantly, the loss of blood can endanger the patient's life. A largebleeder can quickly cause death and even a small bleeder can causesignificant injury or death over time. Likewise, the leaking of somebody fluids may contaminate the area being operated on.

Cutting and sealing or tying off a blood vessel can be a cumbersomeprocess. If a doctor desires to cut a major vessel, he or she willtypically clamp both sides of where the cut is to be made. Once eachside is clamped, the incision is made and the ends are either tied offor are sealed to prevent blood loss through the vessel after theincision. In a surgery involving many blood vessels, it can be timeconsuming and tiring to properly clamp, cut and tie off or seal eachvessel. This is particularly so if the surgeon has to cut out or cutthrough tissue. Thus, there is a need for an instrument that can simplycut tissue, ducts, etc. while preventing leakage from any ducts.Additionally, there is a need for an improved method of clamping,cutting and sealing a duct or tissue in a human or animal body.

Another consideration in sealing and cutting ducts or tissues isensuring that the sealing and cutting is done generally consistentlyacross the duct or tissue. If the sealing and cutting is done with ascissor-like instrument, more sealing may be applied on one side of theduct or tissue (i.e. the portion closest to the hinge of the surgicalinstrument) than on the opposing side because more force is appliedadjacent the hinge. Thus, it is believed that it would be preferable tohave surfaces which are used to seal and cut ducts or tissue to engagethe tissue generally parallel to one another, thereby providing a moreconsistent seal.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved tissuecutting and sealing instrument.

In accordance with the present invention, a surgical instrument isprovided with at least one active surface or thermally active elementmechanism which has at least one element such that a portion of theactive surface or thermally active element mechanism can be heated to atemperature which seals tissue and a portion of the active surface canbe heated to a temperature which cuts tissue to thereby allow tissue tobe both sealed and cut by the same device.

According to one aspect of the invention, two different energy settingsmay be sent to a thermally active element to seal and then cut tissue.(As used herein thermally active element and active element may be usedinterchangeably to reference an element which is heated to treat, e.g.seal or cut tissue). Thus, a physician may attach the instrument to aduct or tissue being cut, seal the duct or tissue to prevent leakage andthen cut the duct or tissue between sealed portions to disconnect thetwo parts of the duct or tissue. Sealing the duct prior to or concurrentwith cutting it prevents the contents of the duct or tissue from leakinginto a patient's body. This is particularly important when dealing withducts which carry potentially harmful materials like bile or fecalmatter. Thus, in accordance with one aspect of the invention, aninstrument is provided which seals and then cuts a duct. This may beaccomplished by a single grasp of the duct, with the active elementmechanism applying a first, sealing heat and a second, cutting heat toseal and then cut the duct.

In accordance with another aspect of the invention, a single activeelement may seal and cut the duct with the application of heat ofsufficient duration to first seal and then cut the duct.

In accordance with another aspect of the invention, more than one activeelement may be used. If two elements or more are used, a first element(e.g. an outer element) may seal the duct or tissue first, while asecond element (e.g. an inner element) may cut the duct or tissue afterit has been sealed, thereby leaving at least a portion of the sealedduct or tissue on either side of the cut.

According to another aspect of the invention, the system may monitorindicators, such as temperature, standing wave ratio (“SWR”), etc. ofthe active element, or the temperature, electrical impedance,capacitance, conductance, moisture content, etc. in the tissue orcontents of the duct, to determine when sealing and/or cutting has beenadequately applied.

In accordance with another aspect of the present invention, the elementsmay be configured for sealing and cutting a duct or other tissue on oneside, i.e. cutting a piece of tissue off, or from two or more sides,such as cleaving a piece of tissue along a plane.

According to another aspect of the invention, one or more activeelements are disposed on a surgical sealing and cutting instrument whichhas two treatment surfaces which are disposed generally parallel to eachother and remain generally parallel to one another while treatmentsurfaces are moved into engagement with a duct or tissue to be sealedand/or cut to thereby provide a more consistent seal.

In accordance with another aspect of the present invention, the systemmay use a parallel surface movement linkage, such as a pantographlinkage to generally equally engage a duct or tissue and to generallyequally apply heat and pressure to tissue to ensure adequate and evensealing and cutting has been performed.

These and other aspects of the present invention are realized in atissue cutting and sealing instrument as shown and described in thefollowing figures and related description.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present invention are shown and described inreference to the numbered drawings wherein:

FIG. 1 shows a perspective view of a surgical sealing and/or cuttingsystem;

FIG. 2 shows a close-up, fragmented view of a single element tip of asurgical sealing and/or cutting instrument;

FIG. 3 shows a close-up, fragmented view of a double element tip of asurgical sealing instrument;

FIG. 4 shows a close-up, fragmented view of a surgical sealinginstrument showing a sealing barrier;

FIG. 5 shows a close-up, fragmented view of a surgical sealinginstrument with two sealing elements in an alternate configuration;

FIG. 6 shows a close-up, fragmented view of a surgical sealinginstrument with three elements in a configuration similar to that ofFIG. 5;

FIG. 7 shows a close-up, fragmented view of the active surface of asurgical sealing instrument with four elements in a configurationsimilar to that of FIG. 6;

FIG. 8A shows a fragmented, cross-sectional view of an alternateconfiguration for the tip of a surgical sealing instrument according toprinciples of the present invention;

FIG. 8B shows a close close-up, fragmented view of the active surface ofthe surgical sealing instrument shown in FIG. 8A;

FIG. 8C shows a fragmented, side cross-sectional view of an anotheralternate configuration for the tip of a surgical sealing instrumentaccording to principles of the present invention;

FIG. 8D shows an end cross-sectional view of the tip of the surgicalsealing instrument of FIG. 8C.

FIGS. 8E through 8P show end views of alternate configurations of activeelements structures which may be used on tips of a surgical sealingand/or cutting instrument according to principles of the presentinvention;

FIG. 9 shows a close-up, fragmented view of yet another alternateconfiguration of the tips of a surgical sealing instrument;

FIG. 10A shows a close-up, fragmented view of a tip of a surgicalsealing instrument having a heat dispersing element;

FIG. 10B shows an end view of the tip of FIG. 10A;

FIG. 11 shows a close-up, fragmented view of an alternate tip of asurgical sealing instrument;

FIG. 12 shows a fragmented, side view of another tip of a surgicalsealing instrument according to principles of the present invention;

FIG. 13 shows a fragmented, top view of the tip of FIG. 12;

FIG. 14 shows a fragmented, side view of the tips of a surgical sealinginstrument;

FIG. 15 shows a perspective view of a surgical instrument havingcooperating elements;

FIG. 16 shows a perspective view of another surgical instrument made inaccordance with the present invention;

FIG. 17 shows a perspective view of another surgical instrument havingcooperating elements

FIGS. 18 and 19 show surgical instruments being used on tissue inaccordance with the present invention;

FIG. 20 shows a close-up, side view of the parallel movement surgicalsealing and cutting tool in a nearly closed position;

FIG. 21 shows a side view of the parallel movement surgical sealing andcutting tool of in an open position;

FIG. 22 shows a side, fragmented view of a parallel movement surgicalsealing and cutting tool operable through a catheter or cannula withpistol grip, the sealing tool being in an open position;

FIG. 23 shows the surgical sealing and cutting tool of FIG. 22 in aclosed position;

FIG. 24 shows a side, plan view of the surgical sealing and cutting toolof FIG. 22;

FIG. 25 shows a close-up, side view of a parallel movement end for asurgical sealing and cutting tool;

FIG. 26 shows a parallel movement surgical sealing and cutting tool withfinger rings;

FIG. 27 shows a parallel movement surgical sealing and cutting tool witha squeeze grip;

FIG. 28 shows a side view of an alternate embodiment of a surgicalinstrument made in accordance with principles of the present invention;and

FIG. 29 shows a chart correlating estimated tissue effects withtemperature.

It will be appreciated that the drawings are illustrative and notlimiting of the scope of the invention which is defined by the appendedclaims. The embodiments shown accomplish various aspects and objects ofthe invention. It is appreciated that it is not possible to clearly showeach element and aspect of the invention in a single FIGURE, and assuch, multiple figures are presented to separately illustrate thevarious details of the invention in greater clarity. Similarly, notevery embodiment need accomplish all advantages of the presentinvention.

DETAILED DESCRIPTION

The invention and accompanying drawings will now be discussed inreference to the numerals provided therein so as to enable one skilledin the art to practice the present invention. The drawings anddescriptions are exemplary of various aspects of the invention and arenot intended to narrow the scope of the appended claims. Furthermore, itwill be appreciated that the drawings may show aspects of the inventionin isolation and the structures in one figure may be used in conjunctionwith structures shown in other figures.

Tissue sealing may be used to construct a barrier between two or moreportions of tissue or duct, or may be used to repair damaged tissue. Inmany cases, the tissue or duct may provide a pathway for delivery ofmaterial, such as eggs in a fallopian tube or blood in a blood vessel. Abarrier may thus prevent functional operation, in the case of thefallopian tube, or even prevent leakage, such as in the case of theblood vessel. The barrier may also prevent contamination, by closing apotential entrance or exit for contaminants. In some cases, it may bedesirable to cut the tissue apart after sealing. Each portion ofseparated tissue may retain some of the seal. Thus, the tissue seal mayact as a barrier to prevent contents of the tissue exiting and/or othercontaminants entering the cut tissue. Likewise, tissue having an openwound or otherwise needing to be sealed off can be sealed to close thewound and prevent entry of contaminants or to prevent exit of materialfrom the tissue.

For example, tissue sealing and cutting may be used for tubal ligation.A fallopian tube may be sealed and then cut. By sealing the fallopiantube, eggs may be prevented from navigating the fallopian tubes andentering the uterus. However, to ensure that the flow of an egg into theuterus is not possible, the sealed tube is ligated as well. Similarly,blood vessels may be sealed to stop blood flow prior to being cut toprevent bleeding during and immediately after the cut. As will beexplained below, ferromagnetic covered conductors may provide advantagesin sealing and cutting ducts and other tissues, including reduced cost,simplicity of operation and increased effectiveness in tissue sealingand cutting instruments.

In FIGS. 1 to 19, there are shown tissue sealing and cutting instrumentsin accordance with one aspect of the present invention. In FIGS. 20 to28, there are shown surgical instruments in accordance with anotheraspect of the present invention, and which may be used in conjunctionwith the tissue sealing and cutting instruments discussed in FIGS. 1 to19. Parallel surface movement may include a ferromagnetic coveredconductor based tissue sealing and cutting instrument described in FIGS.1 to 19, along with other sealing and cutting technologies. In FIG. 29,a chart of estimated temperature correlation to tissue effects is shown.

Turning now specifically to FIG. 1, a perspective view of a handheldsealing and cutting instrument 10 and system 15 is shown. Many surgicalprocedures require cutting or ligating ducts, such as blood vessels, orother vascular tissue. Due to the inherent spatial considerations of thesurgical cavity, surgeons often have difficulty suturing vessels orperforming other traditional methods of controlling bleeding, e.g.,clamping and/or tying-off transected blood vessels. By utilizing asurgical sealing and/or cutting instrument 10, a surgeon can cauterize,coagulate/desiccate and/or simply reduce or slow bleeding.

For treating larger vessels, a surgeon may opt to seal the tissue orvessel. Tissue sealing is fundamentally different than simplycoagulating or cauterizing vessels. For the purposes herein,“coagulation” is defined as a process of desiccating tissue wherein thetissue cells are ruptured and dried. “Duct sealing”, “vessel sealing” or“tissue sealing” is defined as the process of liquefying the collagen inthe duct, vessel, tissue, etc. so that it reforms into a fused mass withlimited demarcation between adjacent tissue structures. In order toeffectively seal larger ducts (or tissue) two predominant parametersmust be accurately controlled—the pressure applied to the duct or tissueand the amount of heat which is conducted from the tip 20A and/or tip20B to the duct or tissue.

It will be appreciated that the surgical sealing and cutting instrument10 varies from many prior art electrosurgical tools in that in theinstrument of the present invention heat is generated directly in anactive element 110 located on tip 20A and/or 20B. This is in contrast tomany electrosurgical instruments, such as bipolar or monopolarinstruments, which use one or more probes to direct electrical currentinto tissue where the resistance to the electrical current generatesheat in the tissue rather than at a thermal element. In other words, athermal instrument generates heat and applies the heat to the tissue,while monopolar and bipolar devices pass electricity into the tissuewhich results in heat being developed in the tissue.

In use the sealing and/or cutting instrument 10 has tips 20A, 20B whichmay be placed around or on opposing sides of a duct or tissue to besealed. The tips 20A and 20B may be placed at the end of arms 30A, 30Bwhich are held in a user's hand. A user may squeeze the arms 30A, 30B ofthe instrument together causing the tips 20A, 20B to provide pressure onthe duct or tissue. Electrical energy may then be directed to an activeelement 120 on the active surface 40 of tip 20A and/or 20B to heat thethermally active element 120. (It will be appreciated that the activeelement could be applied hot to the duct, or could by applied and thenheated). The heat generated in the active element is applied to the ductor tissue to cause the duct or tissue to seal. In accordance with oneaspect of the invention, a second energy level may be applied to theactive element 110 (or a separate active element) to heat the activeelement 110 to a second temperature that is sufficient to cut the ductor tissue apart. This may be accomplished using one element 110 or byseparate elements 110, 120. Power may be received by the instrument 10through a cable 50.

Alternatively, electrical energy may be delivered to one or more activeelements, such as active elements 110, 120, substantially simultaneouslyto seal and cut the duct or tissue. Under such circumstances, activeelement 110 may be configured to provide a higher thermal density ascompared to the thermal density provided by active element 120. (As usedherein “thermal density” means the rate at which thermal energy isconducted into a duct or tissue.) Thus, the process of sealing andcutting a duct or tissue can be initiated substantially simultaneously,rather than sequentially, to reduce the amount of time it would take asurgeon to seal and cut the duct or tissue. As explained in more detailbelow, it will be appreciated that a single active element having asurface may be shaped to provide a higher thermal density to the duct ortissue at a particular location along the surface. Thus, a single activeelement may be used to both seal and cut a duct or tissue according toprinciples of the present invention.

According to one aspect of the invention, the active element 110 (and/oractive element 120) may be formed by a conductor having a ferromagneticcoating to form a thermally active element. As used herein, the term“ferromagnetic,” “ferromagnet,” and “ferromagnetism” refers to anyferromagnetic-like material that is capable of producing heat viamagnetic induction, including but not limited to ferromagnets andferrimagnets. It is not intended that such materials must be heatedexclusively by magnetic induction unless otherwise indicated and suchmay acquire heat from resistive heating, eddy currents, etc., inaddition to magnetic induction. Power, such as a radio frequency (RF)waveform, may be provided to the conductor. The RF energy may travelalong the conductor's surface in a manner known as the “skin effect”.The current density is generally greatest at the surface and decreasesin magnitude further into the material where the electric fieldapproaches zero. The depth at which the skin effect current is reducedto about 37 percent of its surface value is referred to as the skindepth and is a function of the electrical resistivity, the magneticpermeability of the material conducting the current, and the frequencyof the applied alternating RF current.

The alternating RF current in the conductor's surface produces analternating magnetic field, which may excite the domains in theferromagnetic portion 65. As the domains realign with each oscillationof the current, hysteresis losses in the coating may cause inductiveheating. Heating of the ferromagnetic portion 65 due to hysteresis lossceases above the Curie point because the material loses its magneticproperties.

According to one aspect of the invention, the ferromagnetic coating mayhave a thickness of approximately 4 to 5 skin depths. As the powerpasses through the conductor, heat is produced in the ferromagneticmaterial. For the purposes herein, the heat produced in theferromagnetic material may be referred to as “ferromagnetic heat” or“ferromagnetic heating” and includes heat produced by magnetic inductionor related mechanisms caused by delivering electrical energy from apower source to a ferromagnetic coated conductor in a closed circuit. Asexplained above, heat may also be generated in the ferromagneticmaterial due to resistive heating, eddy currents, etc., however,ferromagnetic heat and ferromagnetic heating excludes heat generated byan electrosurgical element that is used to direct electrical energy intotissue to cause heating of the tissue directly, such as a bipolar ormonopolar instrument. Thus, it is anticipated that the principle sourceof heat will be current passing through the thermally active elementrather than current passing through tissue adjacent thereto.

When the ferromagnetic coating is thin relative to the conductor, theferromagnetic coating can quickly heat to temperatures which will sealand/or cut tissue, and then rapidly cool to a temperature where theferromagnetic coating will not even burn the skin within a very shorttime period. For example, a tungsten conductor having a diameter ofabout 0.375 mm and a ferromagnetic coating of a Nickel Iron alloy (suchas NIRON™ available from Enthone, Inc. of West Haven, Conn.) about thetungsten conductor about 0.0375 mm thick can be used as the element.Multiple different frequencies can be used, including frequencies from 5megahertz to 24 gigahertz. Further, a ferromagnetic covered conductormay be comprised of a ferromagnetic material generally surrounding anelectrical conductor (either touching or not touching the conductor),and which produces heat when electrical energy is supplied to theconductor. A more detailed discussion of powering ferromagneticcoated/covered conductors to generate heat sufficient to seal and/or cutthrough tissue is described in more detail in U.S. Publication No.US-2010-0268207-A1 and US-2010-0268210-A1, which are expresslyincorporated herein in their entirety. It will be appreciated thatimproved heat may be obtained by a ferromagnetic coating whichcompletely circumscribes the conductor along the portion desired to beheated.

Energy may be provided by a power supply 60 through the cable 50 to thehandheld sealing and/or cutting instrument 10. The energy may be, forexample, an oscillating current, such as an alternating RF signal. Thepower supply may include settings 70, displays 80 and one or morecables, such as cable 50. The current power setting may be controlled bya switch 90 on the forceps or foot pedal 100 connected to the powersupply by a cable or through wireless communication. Current may bepassed from the power supply 60, through the cable 50, through theinstrument 10 and along the conductor through the ferromagnetic portionand back to the power supply with the vast majority of the currentstaying in the conductive pathway of the tool rather than beingtransmitted through tissue.

The handheld sealing and/or cutting instrument 10 may have one or moreactive surfaces 40. In one embodiment, the active surface is only on tip20A. In another embodiment, an active surface may be on both tips 20Aand 20B. For example, tip 20B may be a mirror image of tip 20A. A singleactive surface 40 may be desirable and cost efficient for smaller ductsor tissues to be sealed. Multiple active surfaces may be desirable forwork on larger tissues, as the heat may be more consistently presentedto the tissue.

The active surface 40 may include one or more active element 110, 120.The active element may be embedded in a layer of material at the activesurface 40 or may extend outwardly from or located adjacent to theactive surface 40 so that it is positioned away from the surface of theforceps tips 20A, 20B. Thus, the elements 110, 120 may be configured toseal and/or cut when the surface 40 touches tissue, or may seal or cutprior to the surface 40 engaging the tissue. Moreover, the element(s)110, 120 may themselves be the surface which engages the tissue.

It will be appreciated that the active element(s) 110, 120 on each ofthe tips 20A and 20B may be activated at the same time, or one or bothmay be operated separately. Thus, for example, if a surgeon needs toseal a small vessel or other duct, he or she may activate sealing tip20A or 20B and then activate both when encountering a larger vessel orduct.

Turning now to FIG. 2, a close-up view of a single element tip, such astip 20A, of a handheld sealing instrument is shown. In one embodiment,tip 20A may include an active surface 40 with a single active element110, which may be loop or shaped as an elongated arch, i.e. an arch withtwo arms extending from the curved portion. The active element 110 maybe a material which will heat sufficiently to seal and/or cut human oranimal ducts or tissue. The active element 110 may be, for example, aconductor 104 forming a closed circuit with a power source and having aferromagnetic coating 114 disposed on the conductor. The single activeelement 110 may be able to function with at least two energy settings: asetting for sealing tissue together and a setting for cutting throughtissue.

For example, a surgeon may use pressure to apply the active surface 40to a blood vessel or other duct. This may include the blood vessel beingdisposed across the arms of the active element extending from the art.The surgeon may then control power delivered to the ferromagneticcovered conductor forming the active element 110 by activating a firstpower setting causing the blood vessel or other duct to seal or weldclosed, at two locations depending on the distance between the arms. Ifneeded, the surgeon may repeat the sealing on adjacent blood vesseltissue to provide a wider seal. The surgeon may then place the activesurface 40 in the middle of the sealed tissue (or leave the activesurface 40 where it is, if the surgeon did not move it). The surgeon mayactivate a second power setting to cause a portion of the sealed bloodvessel or other duct to be cut with heat generated in the ferromagneticcoating of the active element 110. Thus the blood vessel or other ductmay be sealed closed from contamination and/or leakage while beingseparated into two parts (or being sealed before being cut and thenhaving the open end cut off distal to the seal). It will be appreciatedthat there are several ways for controlling whether sealing or cuttingheat is applied, such as by regulating the duty cycle to control theamount of heat being generated in the ferromagnetic coating 114.

Turning now to FIG. 3, a side view of a double active element tip of ahandheld sealing instrument is shown. In one embodiment, a tip 20A mayinclude an active surface 40 with two active elements 110, 120 which arecontrolled together or separately, or by two active sub-elements 130A,130B (i.e. two portions of a common element) which may be controlledtogether, such as a pair of ferromagnetic covered conductors. For easeof reference, the conductors may be referred to as separate elements110, 120 regardless of whether a single element with two parts or twoseparate elements etc., is used, unless specifically designated as oneor the other. Examples of sub-elements, as the term is used herein, mayinclude an active element comprising a conductor having a plurality ofspaced apart ferromagnetic coatings thereon, an active elementcomprising a conductor having a first coating of a first ferromagneticmaterial and a second coating of a second ferromagnetic materialdifferent than the first ferromagnetic material, etc. It will be furtherappreciated that while two elements or sub-elements are shown, an activesurface 40 having a larger number of elements or sub-elements may beused for a variety of purposes.

The active element(s) 110, 120 may use a separate power setting for eachsub-element 130A, 130B or conductor 104. The outer sub-element 130A orelement 120 may be configured for a sealing temperature range, such as atemperature range sufficient to heat the tissue to about 58° C. to 200°C. or more preferably 58° C. to 62° C. The inner element 130B or element110 may be configured for a cutting temperature, such as a temperaturerange sufficient to heat the tissue to about 200° C. to 500° C., or morepreferably 200° C. to 400° C. By using an outer sub-element 130A orelement 120 to seal and an inner sub-element 130B or element 110 to cut,the inner element/sub-element may avoid cutting the sealed portions of aduct or vessel by cutting in between the seals. (It will be appreciatedthat inner and outer are used for convenience only and are not intendedto limit the geometry of the active elements 110, 120.) When a sealingelement and a cutting element are used, the sealing element may beabove, below, on either side or any other position relative to thecutting element which is desired by the surgeon. The result of a ductbeing disposed across the active elements 110, 120 will be two seals andtwo cuts between the seals, thus clearly terminating flow through theduct and sealing the duct adjacent the cut which minimizes the risk ofaccidentally cutting through the seal.

Elements 110 and 120 are shown as having a generally loop or curve-shapeend with arms extending therefrom. Additionally, the thermally activeelements 110, 120 are shown as being generally parallel to one another.This allows the element 100,120 to be placed on a duct with the lengthof the loop generally perpendicular to the duct with the outer element120 sealing the duct and the inner element 110 cutting the duct toremove a small segment and leave sealed segments on either site of thecuts. It will also be appreciated that in certain surgeries, differentconfigurations may be desirable depending on the orientation of theducts which are to be sealed. Any such geometries are intended to becovered by the claims unless specifically limited therein.)

For example, a surgeon may use pressure to apply the active surface 40to a blood vessel. The surgeon may then cause the outer element 120,which may be a ferromagnetic covered or coated conductor, to receive afirst power setting causing the blood vessel to seal or weld closed. Thesurgeon may then activate a second power setting to the inner element110, which may be a ferromagnetic covered or coated conductor, causingan inner portion of the sealed blood vessel to be cut out of the bloodvessel. The same procedure may be used with other ducts as well.

It will be appreciated that the active surface may be used both to cutan intact duct, for example to both seal and cut a fallopian tube, or toseal and then cut off the end of a duct which has already been cut, suchas sealing off a severed blood vessel and then cutting off the excessvessel beyond the seal, if necessary. Thus the blood vessel may besealed closed from contamination and/or leakage while being separatedinto two parts or cleaned up after being cut, if necessary.

Turning now to FIG. 4, a side view of a sealing barrier distance 140 ofa handheld sealing instrument is shown. The sealing barrier distance 140between the outer sub-element 130A (or element 120) and innersub-element 130B (or element 110) may determine the amount of sealedtissue remaining on each side of a cut performed by the innersub-element 130B. Depending on the tissue, the sealing barrier distance140 may be adjusted. This may be done by selecting forceps 10 (FIG. 1)with tips 20A or 20 b having sub-elements 130A and 130B at a desireddistance, by having one of the sub-elements be adjustable, or by havingforceps with one tip 20A having a first distance between thesub-elements, and the other tip 20B having a different distance betweenthe sub-elements so that the surgeon can choose which tip to use.

According to one aspect of the invention, the distance may be adjustedas the outer and/or inner active elements may be malleable. A tiplinkage may move the outer and/or inner active elements to increase ordecrease distance between the outer and inner active elements.

Active elements may include multiple different technologies. In somecases, two technologies may be combined. For example, a bipolar elementmay be used as the outer sealing element, while a ferromagnetic coveredconductor may be used to cut the tissue as an inner element, or viceversa. Ferromagnetic covered conductors may be desirable for manyapplications because of their ability to quickly heat and cool, as wellas the small amount of tissue damage beyond the point of contact. In oneembodiment the ferromagnetic coating circumscribes the conductor tofacilitate inductive heating.

The system may also incorporate sensors to aid in the determination ofappropriate sealing times and cutting application times. The system maymonitor the temperature, standing wave ratio (“SWR”), etc. of eachactive element, or the temperature, conductivity, moisture content, orimpedance or some combination thereof, of the tissue. In one embodiment,the system automatically seals and then cuts the tissue when the surgeonapplies the instrument to tissue and activates the instrument. Thiscould be done, for example, by monitoring the moisture content of thetissue. During the sealing step, the tissue will lose moisture contentto a point, at which cutting will begin. Thus, moisture content passingbeyond a desired threshold can be used to raise an indicia that sealingis complete and cutting has or will begin.

Likewise, the system may monitor temperature over time (using, forexample, a sensor as shown in FIG. 17) and determine when appropriatesealing has been completed before the cut energy is applied. This can bedone by monitoring the temperature of the element which will tend tostay near a fixed temperature until sealing is complete, and thensuddenly rise as it cuts. Alternatively, the system may monitor maymonitor the temperature, electrical properties, or some othercharacteristic, of the tissue or duct, using a sensor (see e.g. FIG. 17)located on one or both of the tips 20A and 20B. Thus, the temperature,electrical properties, etc. of the tissue or duct can be monitoredacross from, or adjacent to, the sealing and/or cutting elements.According to one aspect of the invention, a light or sound may beemitted from the instrument or power supply to notify the surgeon when aphase appears to be completed. Thus, the surgeon may listen for a firstsound or see a first light to know that a sealing phase is completed.The surgeon may then activate the cutting phase and await a second lightor sound to know that the cutting phase is completed and the instrumentmay be removed, or the instrument may automatically perform each stepand provide notification when each is complete.

During a procedure, power delivery to the sealing instrument 10 may becontrolled by varying the amplitude, frequency or duty cycle of thealternating current waveform, or alteration of the circuit to affect thestanding wave driving the ferromagnetic coated conductor.

Turning now to FIG. 5, there is shown an alternate arrangement of anactive surface 40. In FIGS. 1-4, the active element(s) 110, 120 weregenerally U-shaped as may be beneficial for sealing and cutting out aportion of a duct. There are situations, however, where it is desirableto cut off or cut out a portion of tissue or a duct which involvessealing and cutting tissue over an elongate area. Thus, rather thanusing an active surface 40 having U-shaped active element(s) 110, 120,FIG. 5 shows active elements which may be generally linear and generallyparallel and which may be used in a manner somewhat analogous to use ofa pair of scissors. (As explained in more detail below, the activeelement(s) 110, 120 shown in FIGS. 5-7 may be formed from a flattenedconductor 104 covered by a ferromagnetic coating 114.) If desired one orboth conductors 104 and/or the coatings may be flattened.

As shown in FIG. 5, one element 120 may be used for sealing, whileanother element 110 may be used for cutting. Thus, a surgeon or otheruser would engage the tissue and activate the sealing element 120 andthe cutting element 110. This may be done simultaneously or sequentiallydepending on the time necessary for the sealing element 120 toadequately seal off fluid flow through the tissue. By advancing theactive surface 40 along the tissue, and activating the active elements110 and 120, the tissue on the side of element 110 opposite element 120would be cut off.

While reference is made to an active surface 40, it will be appreciatedthat the active element may be in the active surface or extend outwardlyfrom the active surface depending on the intended use and the desires ofthe user. Thus, it will be appreciated that active surface 40 itselfneed not seal or cut tissue.

Turning to FIG. 6, there is shown an alternate configuration of anactive surface 40. The active surface 40 may include two sealing activeelements 120 and a cutting active element 110 disposed therebetween. (Asused herein, a sealing active element is a thermally active elementwhich is heated to seal tissue and a cutting active element is athermally active element heated sufficiently to cut tissue. It will beappreciated that one element could function as both depending on how itis controlled.)

In use the active surface 40 may be placed along a tissue to be cut. Thesealing active elements 120 may be used to seal the tissue on eitherside of the cutting active element 110 and the cutting active elementused to cut the tissue to ensure that flow between opposing sides doesnot continue. Thus, for example, if flow through a duct needed to beprevented, the duct will be sealed on either side of the cut, therebyensuring both sealing and cutting of the duct.

Turning now to FIG. 7, there is shown yet another configuration of anactive surface 40. The active surface 40 may include two sealing activeelements 120 which are spaced apart and two cutting active elements 110which are spaced apart a desired distance 126. In use the active surfacecan be placed on a tissue or duct to be cut (with the length generallyperpendicular to the length of the duct) and the active elements 110,120 energized to seal and cut the tissue or duct. In addition to sealingand/or cutting the tissue or duct, the arrangement of the cutting activeelements 110 will cut out a strip of the tissue or duct. This may bedesirable when the active elements are being used to remove a diseasedportion of tissue, or where is it desirable to remove a segment of aduct to ensure that flow therethrough has been terminated. For example,in tubal ligation, it is often required to affirmatively remove asection of the fallopian tube to ensure that there is no risk ofpregnancy in the future. With the active surface of FIG. 7, both sidesof the cut will be sealed and a segment between the cuts can be removedfor adequate reassurance that flow through the fallopian tube is nolonger possible.

Turning now to FIGS. 8A and 8B, there is shown an alternateconfiguration for the tip, generally indicated at 20A, of a surgicalsealing instrument according to principles of the present invention.Similar to the tips described above, the tip 20A may include a thermallyactive element 110 comprised of a conductor 104 having a ferromagneticcoating 114 disposed thereabout to form a ferromagnetic heating region.The active element 110, however, may form a generally flat, planarsurface. The generally planar surface of the active element may beformed by flattening a section of a conductor wire 104 and plating acoating of ferromagnetic material 114 on the flattened conductor 104such that the ferromagnetic coating 114 substantially covers the entireouter surface of a length of the flattened conductor 104. (The coating114 may extend completely around the conductor 104 if desired). Theflattened conductor 104 may form a closed circuit with a power sourcedirectly or via intervening conductors such that applying electricalenergy across the flattened conductor causes substantial uniformferromagnetic heating along the ferromagnetic region of the activeelement 110.

The flattened conductor may extend along an arm 30A of a sealing and/orcutting instrument of the present invention, such that electrical energysupplied from a power source travels towards the ferromagnetic material114 through section 104 a of the conductor 104, away from theferromagnetic material 114 through section 104 b of the conductor 104,and back to the power supply. (It will be appreciated that,alternatively, electrical energy could travel towards the ferromagneticmaterial 114 through section 104 b and away from the conductor throughsection 104 a). Arm 30A may include a thermally and/or electricallyisolating material 106 to substantially prevent transfer of heat and/orelectrical current to the arm 30A of the surgical sealing and/or cuttinginstrument. Additionally, an electrically isolating material 116 may bedisposed between sections 104 a, 104 b of the conductor 104 to preventcurrent from bypassing the ferromagnetic material.

As will be appreciated, the active element 110 shown in FIGS. 8A and 8Bwill have a larger surface area for contacting a duct or tissue to besealed and/or cut. By applying heat to a duct or tissue using an activeelement 110 with a larger surface area a better seal may be createdalong the duct or tissue.

Turning now to FIG. 8C, there is shown a fragmented, sidecross-sectional view of another configuration for tips of a surgicalsealing and/or cutting instrument according to principles of the presentinvention. For clarity purposes, the cross-hatching of the activeelements 110, 120 has been removed. FIG. 8D shows an end,cross-sectional view of the thermally active elements of FIG. 8C. Thetips 20A, 20B may include active element(s) 110, 120. Each activeelement 110, 120 may comprise a conductor 104 having a ferromagneticcoating 114 disposed thereon, similar to the active element shown inFIGS. 8A and 8B. However, it will be appreciated that only one activeelement need generate thermal energy which is conducted to a duct ortissue according to principles of the present invention as explained inmore detail below. As best shown in FIG. 8D, the active element 110 maybe formed such that there is a cutting zone 115, formed by a protrusion,rib, etc., and a sealing zone 103 in the ferromagnetic heating region.As shown in FIG. 8D the cutting zone 115 is a protrusion which extendsaway from the generally planar surface which forms the sealing zone 103of the active element. When a surgeon squeezes the arms 30A, 30B of theinstrument together to cause the active elements 110,120 to contact theduct or tissue, an increased amount of pressure will be applied to theduct or tissue at the location of the protrusion of the cutting zone115. Heat generated by active elements 110, 120 is conducted to the ductor tissue, with a higher thermal density at the location of the cuttingzone 115. Thus, a better seal may be achieved at the location of thecutting zone 115, or the duct or tissue may be severed along the cuttingzone 115 due to the increased amount of pressure while areas of the ductor tissue in the sealing zone 103 may be sealed.

As explained above, a higher thermal density is required to cut a ductor tissue as compared to sealing the duct or tissue. To increase thethermal density along the cutting zone 115 the pressure applied and/orthe heat conducted to the duct or tissue at the location of the cuttingzone must be increased. Thus, as shown in FIG. 8D, the protrusion mayprovide increased pressure applied to the duct or tissue at the locationof the cutting zone 115, thereby allowing the duct or tissue to be cutalong the cutting zone 115 while being sealed along sealing zones 103.Thus, a single application can be used to both cut and seal.

Active elements may be constructed to have a variety of shapes in orderto create a cutting zone and sealing zone similar to the cutting zone115 and 103 discussed in connection with FIG. 8C. For example, FIGS. 8Ethrough 8P show various active elements having different shapes orelements which may be used to create a cutting zone and sealing zone.These active elements could be used in conjunction with forceps or otherthermally active surgical instruments shown herein.

It will be appreciated that the scope of the invention is not to belimited by the embodiments shown in FIGS. 8E through 8P, rather, FIGS.8E through 8P are being provided for illustrative purposes only.Furthermore, for clarity, FIGS. 8E through 8P only show the activeelements 110, 120, but it will be understood that the other elements ofa sealing and/or cutting instrument according to principles of thepresent invention disclosed herein (e.g. the sealing and/or cuttinginstrument of FIG. 8C) would be associated with the active elements 110,120 shown in FIGS. 8E through 8P.

While FIG. 8E shows an active element 110 (similar to the active element110 shown in FIG. 8B) having a ridge extending along the planar surfaceof the upper active element 110 to form the cutting zone 115 and sealingzones 103 adjacent to the cutting zone 115, the projection forming thecutting zone 115 could be on the lower active element 120. (It will beappreciated that elements 110 and 120 as shown in FIGS. 8A-8P canfunction both as a cutting element and a sealing element or portionsthereof.

According to one aspect of the invention the structure shown as element120 may not be a ferromagnetic coated conductor. In fact, the structure120 may only be a support structure (e.g. not a thermal element) whichprovides a compressive surface opposite active element 110.Alternatively, the active element 120 may generate heat to seal and/orcut a duct or tissue and have a ridge forming a cutting zone 115, whilethe active element 110 is a support structure for use as a compressivesurface opposite active element 120 as shown in FIG. 8F.

FIG. 8G shows and active element 110 similar to that shown in FIG. 8E.The active element 120, however, differs from the active element 120shown in FIG. 8E in that the active element 120 of FIG. 8G comprises arecess 117, or quasi-complimentary receptacle, to alter the compressionforce applied to a duct or tissue when the active elements 110 and 120are squeezed together to engage the duct or tissue.

FIG. 8H shows and active element 120 with a sharp cutting zone 115 tofacilitate cutting of a duct or tissue. The compressive force applied toa duct or tissue along the cutting zone 115 may be altered by includinga recess 117 on active element 110 positioned generally opposite thecutting zone 115. While not shown in the drawings for brevity, theactive element 110 of FIG. 8G could be combined with the active element120 of FIG. 8H to form protrusions in alignment or out of alignment withone another to provide a desired cutting dynamic.

FIGS. 8I and 8J show an arcuate active element 110 and an arcuate activeelement 120, respectively. A cutting zone 115 may be formed about theapex of the curved or arcuate active elements 110 (FIG. 8I) and 120(FIG. 8J) due to the increased amount of compressive force that will beapplied to a duct or tissue at this location as compared to thecompressive force that will be applied to the duct or tissue adjacentthe cutting zone 115 at sealing zones 103.

The compressive force applied along the cutting zone 115 shown in FIGS.8I and 8J may be altered by matching the curved or arcuate activeelements with an opposing active element that is also curved, as shownin FIGS. 8K and 8L. For example, the arcuate active element 120 shown inFIG. 8K may be paired with an arcuate active element 110. The degree ofcurvature of the arcuate active element 110 may be less than the degreeof curvature of active element 120, and the degree of curvature ofeither (or both) the active element 120 and 110 can be adjusted to alterthe compressive force applied to a duct or tissue. As shown in FIG. 8K,the arcuate active element 120 may curve in the same direction asarcuate active element 110 in a quasi-complimentary orientation.Alternatively, the compressive force along cutting zone 115 may besubstantially increased relative to the compressive force applied alongsealing zone 103 by having arcuate active elements curved in oppositedirections from each other, such as is shown in FIG. 8P.

Cutting zones 115 and sealing zones 103 may also be created by alteringthe thermal conductivity along the surface of one of the activeelements, as shown in FIGS. 8M and 8N. For example, active element 120in FIG. 8M may be a support structure for providing a compressivesurface opposite active element 110. One or more heat sinks 121 may bedisposed adjacent the active element 110 (FIG. 8M) or 120 (FIG. 8N) toform a sealing zone 103 along a portion of the active element 110 todraw away a greater amount of heat from the active element on a portionthereof. As shown in FIGS. 8M and 8N, a the spaced apart heat sinks 121disposed adjacent to the active element 120 and 110, respectively, maybe used to create a cutting zone 115 located generally in the center ofthe active elements with sealing zones 103 on both sides of the cuttingzone 115, as the heat in the center portion is not drawn away by theheat sinks.

FIG. 8O also shows an active element 110 having a cutting zone andsealing zones 103. Rather than drawing heat away from sealing zones 103as discussed above relative to FIGS. 8M and 8N, a heat spreader 123 ofmoderate thermal conductivity may be used to concentrate a greateramount of heat along a cutting zone 115 as compared to a sealing zone103. As shown in FIG. 8O, the heat spreader 123 may be disposed adjacentthe active element 110 in a central location so as to create a cuttingzone 115 located generally in the center of the active element 110 witha sealing zones 103 on both sides of the cutting zone 115

Turning now to FIG. 9, there is shown a fragmented, perspective view ofthe tips 20A, 20B of a sealing and cutting instrument, such as sealingforceps, according to one aspect of the invention. In contrast to FIG.1, tip 20A in FIG. 9 may have an active element 110 comprised of only arigid loop 116 forming a sealing and/or cutting element. The rigid loop116 may be opposed to surface 44 of tip 20B and aligned in a generallyhorizontal orientation which would provide sealing and/or cutting at twopoints when disposed perpendicular to a duct. It will be appreciated,however, that the rigid loop 166 may be aligned in differentorientations to achieve a more specific therapeutic effect, such asaligned vertically to achieve a single, more rapid cut.

Rigid loop 116 may be formed of a conductor wire having a ferromagneticmaterial disposed along at least a portion thereof, typicallycircumferentially about a portion of the conductor wire. The conductorwire may be of a sufficiently large gauge so that the rigid loop 116substantially resists deformation when tips 20A and 20B are used toapply pressure about a tissue or duct. For example, to seal an artery itis important that sufficient pressure be applied to the artery so thatthe endothelium of opposing walls of the artery are adjacent each other.Then power may be supplied to the active element 110 to seal the artery.It will be appreciated that conductor wire is used herein forconvenience only and those skilled in the art will appreciate that otherconductive material may be used to form the rigid loop 116.

Sealing and cutting of a tissue or duct using tips 20A and 20B may occursequentially. For example, the tips 20A, 20B may be placed around tissueto be sealed and the tips forced together so as to provide pressure onthe tissue. Power may then be supplied to active element 110 to heat thetissue or duct. Initially, sealing of the tissue or duct will occur asthe active element and/or the tissue or duct may not exceedapproximately 100° C. as water evaporates from the tissue or duct, i.e.the temperature of the active element and/or the tissue or duct may belimited by the phase change of water in the tissue or duct as itevaporates. Once all water has evaporated, the temperature may thenquickly rise to cut the tissue or duct.

It will be appreciated that sealing and cutting of a tissue or duct maybe accomplished by supplying a constant power to the active element 110.For example, a low wattage may be supplied to the active element 110 tocoapt lung tissue. The temperature of the active element may be about100° C. until all water in the lung tissue evaporates. This may takeapproximately 40 seconds when the active element 110 is supplied withabout 30 watts of electrical energy. Once the lung tissue becomesdesiccated the temperature of the active element 110 may suddenly riseto commence cutting of the tissue.

Turning now FIGS. 10A and 10B, there is shown an alternate configurationof a tip 20A in perspective and from a cross-sectional view,respectively. Tip 20A may have an active element 110 disposed in a heatdispersing member 118. The heat dispersing member 118 conducts heat awayfrom the active element 110 so that heat may be applied to a tissue orduct more uniformly along an outer surface of the heat dispersingelement 118. Use of a tip 20A having a heat dispersing member 118 may bemore desirable when a therapeutic procedure does not require cutting ofthe tissue or duct. Because heat is less concentrated at a discretelocation along the tissue or duct, it may be treated using tip 20Awithout being cut.

The heat dispersing member 118 may be a material that resists stickingto a tissue when thermal energy is applied to the tissue by activeelement 110, such as Teflon®, Kapton®, etc. It will be appreciated thattissue may stick to the active element 110 until it reaches asufficiently high temperature, e.g. 300° C. However, active element 110may not be used at such high temperatures during some therapeuticprocedures, such as vascular shrinkage in aneurism preparation forclipping. Thus, use of a non-stick heat dispersing member 118 duringsuch procedures may be necessary to avoid tissue sticking to the activeelement 110.

It will be appreciated that use of a non-stick material such as Teflon®,Kapton®, etc., may be used on various surfaces or elements in theembodiments described herein. For example, it may be desirable toinclude a non-stick material on surface 44 opposed to active element 110in FIG. 9 to ensure that heated tissue does not stick to surface 44. Anon-stick material may be desirable in therapeutic procedures involvingwelding, sealing, coapting, and/or homeostasis which involvetemperatures at or below approximately 100° C.

Turning now to FIG. 11, there is shown another configuration of tip 20A.Tip 20A may include active element comprised of a ferromagnetic materialin sheet form, such as Alloy 152. The sheet of ferromagnetic materialmay be placed over a surface mounted inductive coil (not shown) to forman active element 110 and achieve a broad active surface that may beused to treat tissue. Further, direct electrical connection may beprovided to the sheet of ferromagnetic material, instead of inductivecoupling. This may produce sufficient heat to deliver the desiredtherapeutic effect. It will be appreciated that it may be desirable touse a thin sheet of ferromagnetic material as the time to heat and coolthe tip 20A is dependent on the thermal mass of the material.

Referring now to FIGS. 12 and 13, there is shown still anotherconfiguration of tip 20A. Tip 20A may be attached to an arm 30A andinclude an active element 110 having a sealing member 48 and a cuttingmember 112. Sealing member 110 may have a relatively broad surface whichmay be used to seal, weld, or coapt tissue or a duct or to achievehomeostasis. Sealing member 110 may, for example, be a sheet offerromagnetic material disposed on a conductor similar to that describedin FIG. 11, or a ferromagnetic coating plated on a flattened conductoras described, for example, in FIGS. 8A-8C.

The cutting member 112 may be a thin wire, such as a wire coated with aferromagnetic material which may allow a surgeon to cut a tissue or ductat a more precise location. A surgeon may be able to cut a tissue orduct using cutting member 112 and then use the reverse side of the tip,the sealing member 48, to achieve homeostasis. Alternatively, a surgeonmay use the sealing member 48 to seal a tissue or duct and then flip thetip 20A over to make a precise cut using the cutting member 112.

A surgical instrument may include more than one of the tips shown inFIGS. 12 and 13 which are disposed opposite each other as is moreclearly shown in FIG. 14. Tissue or a duct may be grasped betweensealing members 48A and 48B. Sealing members 48A and 48B may then beused to apply pressure to the tissue or duct. Power may then be suppliedto the sealing members to seal the tissue or duct. Once the tissue issealed, a surgeon may use either of the cutting members 112A, 112B tocut and/or remove tissue if needed or desired, or the sealed tissue maybe left as is if there is no need to remove tissue.

While some of FIGS. 1-13 show a single active surfaces or elements onone side of the instrument, it will be appreciated that an instrumentmay have complementary active surfaces 40 or elements 110 which eitheralign with or are slightly offset from the other active surface toensure sealing and cutting of thicker ducts and tissues, such as thatwhich is in FIG. 14. This may be in the context of forceps, scissor-likeinstruments or a host of other surgical devices.

FIG. 15 shows a perspective view of a surgical instrument 200 havingcooperating opposed active surfaces 40 with sealing and cutting elements110, 120 disposed on or extending from the active surfaces in order toseal and cut a duct, tissue, etc., from opposing sides. The surgicalinstrument 200 may be powered by a cable 50 in a manner similar to thatdiscussed with respect to FIG. 1.

The surgical instrument 200 can be used similar to forceps to seal andcut veins and ducts, or can be used in a manner more analogous toscissors. For example, in FIG. 1, active element(s) of the surgicalinstrument 200 are being selectively activated to seal and cut tissue,such as lung tissue, or other tissue in the body. In such a mannerdiseased or damaged tissue can be cut out of the body while also sealingthe remaining tissue against the loss of blood or other fluid andagainst the entry of bacteria, etc. The surgical instrument 200 can beplaced on an initial portion of tissue and the sealing active element(s)(e.g. 120) activated to seal the tissue and then the cutting activeelement(s) (e.g. 110 or the sealing active element at different power)activated to cut through the tissue. The surgical instrument 200 may beadvanced and the procedure repeated until the undesired tissue iscompletely cut away.

Turning now to FIG. 16, there is shown a perspective view of analternate configuration of a surgical instrument 250 for use in thepresent invention. Rather than operating like a pair of forceps as shownin FIG. 15, the surgical instrument 250 functions in a manner moreanalogous to scissors. Each active surface 40 is attached to an arm 254which extends to a pivot point 260 and then to a handle portion 264formed by finger holes 270 or some other gripping structure.

The active surfaces 40 and/or active elements 110, 120 may be formed aspart of the arms 254, or may be attached to the arms, such as by pivots268, to allow the active surfaces or elements to adjust relative to oneanother and apply pressure more uniformly on a tissue than would occurin a scissors where there may be greater pressure adjacent the pivotpoint 260. Thus, the sealing may be more consistent as the activesurfaces 40 and elements 110, 120 remain more parallel.

In use, the surgeon would position the active surfaces 40 along the areato be cut and apply force on the handle portion 264 while power isdelivered through the cable(s) 50 from a power supply to the activeelements to thereby seal and cut tissue. If necessary, the activesurfaces 40 could then be advanced along the tissue and the processrepeated.

FIG. 17 shows a perspective view of a surgical instrument 200 having arigid loop 116 cooperatively opposed to a surface 44. The surgicalinstrument 200 may be powered by a cable 50 connected to a power supplyin a manner similar to that discussed with respect to FIG. 1. Oneadvantage of surgical instrument 200 having a rigid loop 116 is that auser of the surgical instrument 200 may be able to better view thetissue or duct that is to be sealed and/or cut.

A sensor 119 may be disposed in communication with the surgicalinstrument 200. As shown, the sensor 119 may be disposed on the surface44 and used to monitor electrical properties of the tissue or duct. Forexample, when the surgical instrument 200 is being used to seal and cuta tissue, evaporation of water may cause the capacitance of the tissueto change and shift the standing wave ratio (“SWR”) of the appliedelectrical energy. The sensor may detect the shift in the SWR andprovide a signal of the transition from sealing to cutting of the tissueby the surgical instrument. Thus, the sensor 119 may provide the surgeonwith an indication of the effectiveness of the seal and the status ofthe sealing/cutting taking place.

The sensor 119 may also monitor temperature of the interface between theactive element 110 and the tissue. Once a sufficient temperature isachieved to cut the tissue, a signal may be generated to notify thesurgeon that the tissue has been cut or is being cut. Thus, for example,the element 110 may hold at 100° C. for a period of time. If pressure isbeing applied to duct, etc., this will correspond with sealing. Oncesealing it complete, the water in the tissue will be consumed and thetemperature of the element 110 will suddenly rise, indicating transitionin to the cutting phase. To provide control, the instrument 200, or somerelated structure, may advise the physician which phase is currentlybeing undertaken, or it may advise the physician that sealing iscomplete and that cutting can commence.

The surgical instrument 200 may include additional, or alternate,sensors to monitor sealing and cutting of a tissue or duct. For example,a thermocouple may be disposed integrally with the surgical instrumentto monitor temperature as the procedure progresses from sealing tocutting and/or when cutting of the tissue is complete. Alternatively,the electrical properties of the conductor of active element 110 mayindicate when sealing and/or cutting of the tissue is complete. Forexample, if active element 110 is comprised of a tungsten conductorcoated with a ferromagnetic material, then the resistivity of thetungsten conductor may be monitored to determine when sealing and/orcutting is complete. As water evaporates from the tissue, theresistivity of the tungsten conductor may increase. Thus, theresistivity of the tungsten conductor may be correlated with thecompletion of tissue sealing.

FIG. 18 shows a surgical sealing and/or cutting instrument 200 beingused to treat tissue 208. The surgeon may position the tissue 208between the active elements 110, 120. The active elements are thenactuated to seal off a section of the tissue 212. If so desired thesection of tissue 212 can be cut using the instrument 200 and removedfrom the surgical site, thereby leaving the main tissue 208 sealed alongthe incision.

FIG. 19 shows an alternate configuration of a surgical instrument 270being used to cut a tumor 274 from lung tissue. As was mentioned above,the active surface 40 and/or active elements 110/120 need not be linearand may be bendable. In FIG. 19, the elements are disposed in agenerally semi-circular configuration so as to enable sealing around andcutting out of a tumor. (A complementary portion to that shown mayengage the tissue on the opposing side and may lack any active elementsso that it merely engages the tissue, or may have one to two elementsfor promoting sealing and cutting). In use the active elements 110, 120are positioned on the lung tissue just beyond the area to be removed.The elements are then powered from a power supply via cable 50 to sealoff the lung tissue 280 (along thermally active element 120) and to cutthe portion of the lung tissue containing the tumor 274 (along thermallyactive element 110). Thus, the tumor is cut away as the remaining lungtissue is sealed to thereby prevent air and blood leakage, etc.

Turning now to FIGS. 20-28, various tools with parallel linkages areshown which can be used, in accordance with one aspect of the invention,in conjunction with tissue sealing/cutting elements to selectively sealand cut or cut and seal ducts in a human or animal. As tissue bundles orducts to be sealed are larger, parallel surface movement of the one ormore treatment surfaces may be desirable. If an angular movementinstrument is used with a larger tissue bundle, more pressure may beplaced on the proximate portion, i.e. the portion of the bundle or ductthat is closest to the pivot. This leaves the distal portion, i.e. awayfrom the pivot, with less pressure. With less pressure, it is possiblethat the distal portion may receive little to no energy or pressure fromone or more of the treatment surfaces 40, or may not be held insufficient contact with adjacent tissue to form a good seal. Withparallel movement surfaces, the tissue bundle may receive more-equalpressure on the proximate and distal portions. Thus the heat may beapproximately equally distributed along the tissue bundle surface. Thisis particularly important when sealing large ducts or tissues.

For small ducts or tissue bundles, such as small blood vessels, forcepsor jaws on a pivot (similar to scissors) may adequately approximateparallel movement for the small movement required. With larger ducts ortissue bundles, however, it may be desirable to choose a parallelsurface movement linkage as discussed herein.

Turning now specifically to FIGS. 20 and 21, a side view of a parallelmovement surgical sealing and/or cutting instrument, generally indicatedat 10, is shown with the instrument in a nearly closed position (FIG.20) and in an open position (FIG. 21). The instrument may include aparallel movement linkage, generally indicated at 165. Such a parallellinkage has been referred to as a pantograph linkage.

Two instrument halves 160A, 160B are connected by the parallel movementlinkage 165 so as to enable a treatment or active surface 40A (or activeelements 110 which may be embedded in or extend from the treatmentsurface and a treatment or active surface 40B—which may have similaractive elements) to move in parallel with one another. The linkage hastwo arms or bars 180A, 180B that are fixed at one end via fasteners190A, 190B to the two instrument halves 160A and 160B, respectively, andconnected in the middle via a fastener 190C. The opposing end of thebars 180A, 180B may include fasteners 210A, 210B, respectively, or otherconnectors which move in linear tracks 200A, 200B (FIG. 6) in the twoinstrument halves 160A and 160B. When operated, the linkage causes aline defined by fastener 190A and second bar end fastener 210B to remainparallel to fastener 190B and second bar end fastener 210A while thedistance between these lines are adjusted. This X linkage has beenreferred to as a pantograph linkage.

The instrument 10 may be operated with one hand. A user may insert theirfingers into the openings 220A, 220B. Using the fingers, the user mayseparate the instrument halves 160A, 160B causing the instrument tips20A, 20B to separate as well. Alternatively, the instrument halves 160A,160B may be biased by a spring in the open position. A tissue bundle maybe placed between the active surfaces 40A, 40B while the user may causethe instrument tips 20A, 20B to apply pressure to the tissue bundle bysqueezing the instrument halves 160A, 160B together. One or both of theactive surfaces 40A, 40B may contain one or more active elements 110that may be activated at a first energy setting to seal the tissuebundle. The user may then activate the one or more active elements 110(120, etc.) to cut the tissue bundle after sealing. The instrument maythen be removed from the tissue bundle. The instrument 10 can movethrough tissue in a manner similar to scissors, but enables a physicianto seal and cut the tissue, thereby avoiding the need to tie off bloodvessel or sew up the tissue because the tissue was sealed as well asbeing cut.

Turning now to FIGS. 22 through 24, side views of a parallel movementsealing and/or cutting instrument 240 operable through a small accessport with a pistol grip are shown. The sealing and/or cutting instrument240 may be biased into either the open or closed position depending onthe use desired by the physician. In some cases, it may be desirablethat a parallel movement sealing and/or cutting instrument fit within atrocar catheter or other cannula such as a laparoscope, in order to gainaccess to the body. This may be used, for example, when performing alaparoscopic tubal ligation or other laparoscopic procedure. Therefore,a parallel movement sealing instrument may include a configuration tofit within an access port when closed, while facilitating movement ofthe control mechanism outside the access port and actuation of thesealing elements at the opposing end of the sealing and/or cuttinginstrument. While the neck 290 shown in the figures may be short, itshould be recognized that the neck may be extended for applicationsrequiring longer access distance.

The parallel movement sealing instrument 240 (FIG. 22, normally openbias; FIG. 23, normally closed bias) may include a grip 260 trigger 272,bias mechanism 282, neck 290 and instrument end 300. The bias mechanism282 may aid the instrument to reset to a known state, such as open orclosed. The bias mechanism may be a spring or elastic member thatresists stretching and/or compression. The neck 290 may be relativelyshort or long and may include a movement transfer linkage to take forceapplied by the trigger 270 and/or bias mechanism 282 and transfer themovement to the instrument end 300.

The instrument end 300 may include the parallel movement linkage 165that enables a first treatment surface 40A to move in parallel with asecond treatment surface 40B, such as the linkage described in FIGS. 20and 21. One or both of the treatment surfaces 40A, 40B may includeactive elements 110, 120, etc. The treatment surfaces 40A, 40B mayreside on tips 230A, 230B.

A user may apply the instrument by one or more of the following steps:selecting a surgical instrument having substantially parallel surfacemovement; causing the surfaces to be above and below a tissue to treat;reducing the distance between the surfaces so that the surfaces (or theelements if the elements extend from the surfaces) engage the tissue;and/or activating an active element on at least one of the surfaces tothereby seal and/or cut the tissue. In many applications, some force isapplied to the tissue by the treatment surfaces or active elements whilethe tissue is being sealed and/or cut.

More specifically, a user may cause the instrument end 300 to becomeclosed. The user may then insert the instrument 240 into an access portin the body. The instrument end 300 may then be opened and placed arounda tissue bundle, duct, vessel, etc. The user may then apply the trigger270 such that the tips 230A, 230B place pressure on the tissue beingtreated. One or both of the treatment surfaces 40A, 40B may contain anactive element 110 that may be activated at a first energy setting toseal the tissue (via an electric current from a power source asdiscussed above). The user may then activate the one or more activeelements 110 to cut the tissue bundle after sealing. The instrument 240may then be removed from or advanced along the tissue bundle.

In FIG. 22, a normally open parallel movement sealing instrument 240 isshown. The normally open parallel movement sealing instrument may havethe advantage of transferring the pressure applied to the trigger 272 tothe tips 230A, 230B, such that the pressure on the tissue bundle may beregulated by the user's squeeze on the trigger 272.

In FIG. 23, a normally closed parallel movement sealing instrument 240is shown. The normally closed parallel movement sealing instrument mayhave the advantage of consistent applied pressure by the bias mechanism282 and the fact that a user would not be required to maintain pressureon the trigger 270 when closed on the tissue being treated.

Turning now to FIG. 24, a mechanical diagram of FIG. 22 is shown. Anactivation button 310 and trigger linkage 320 may be seen more clearly.The activation button may be used to apply power to the thermally activeelement 110. The trigger linkage 320 may include a post in a trackallowing trigger 272 movements to be translated into linear movement ofa rod 330. The rod 330 may be connected to the parallel movement linkage165, allowing the transfer of force from the trigger 272 to parallelmovement linkage 165.

Turning now to FIG. 25, a parallel movement end 380 for the sealinginstrument is shown. The parallel movement end 380 may be configured ina module 390. In one embodiment, the module 390 may be added toinstruments that use forward and backward linear movement of a rod. Forexample, a sleeve could be attached to the module 390 and the rodattached to one of the bars 180 a or 180 b. As the rod moves forwardlyand rearwardly, the tips 230A, 230B move toward and away from oneanother.

Turning now to FIGS. 26 and 27, parallel movement sealing instruments400, 450 are shown with alternate movement transfer linkages. FIG. 26shows a movement transfer linkage with finger rings. Separation of amoving ring 410 from the stationary rings 420 may cause motion to beapplied to the parallel linkage 430. Depending on how the moving ringand stationary ring are attached to the bars 180A, 180B forming theparallel linkage, moving the moving ring 410 toward the stationary ring420 will either open or close the space between the tips 230A, 230B.

FIG. 27 shows a sealing instrument 450 with a movement transfer linkage430 connected to a handle 440 with a squeeze grip trigger. Applicationof pressure to a front end 470 of the grip may cause the movement of thesqueeze trigger to be transferred to the parallel linkage 430.

FIG. 28 shows a side view of an alternate embodiment of a surgicalinstrument 335 made in accordance with principles of the presentinvention. The instrument 335 is configured with a parallel movementlinkage to keep the active surfaces parallel to one another. Theparallel linkage may include a direct linkage 340. As the trigger 290 issqueezed, the linkage 340 may rotate, advance or otherwise cause amovable tip 370 to approach a stationary tip 360. As the trigger isreleased, the movable tip 370 may withdraw from the stationary tip 360.

The instrument 335 may include one or more active surfaces 40 on tips360, 370. The active surfaces 40 may apply pressure to seal and cuttissue, including ducts such as blood vessels, fallopian tubes, etc., asdescribed above.

While not shown in all of FIGS. 22 through 28, will be appreciated thatthermally active elements would be disposed on opposing sides of thetips and would be disposed in communication with a power source toselectively heat the active elements.

Turning now to FIG. 29, a chart correlating estimated tissue effectswith temperature is shown. It should be recognized that thesetemperature ranges are estimates, and that temperatures may varydepending on multiple factors that may include tissue type, tissuemake-up, and water content. Vascular welding is estimated to occur nearthe range of 58° C. to 62° C. Hemostasis is estimated to occur near therange of 70° C. and 80° C. Searing and sealing is estimated to occurnear the range of 80° C. and 200° C. Incision is estimated to occur nearthe range of 200° C. and 400° C. Rapid ablation and vaporization isestimated to occur near the range of 400° C. and 500° C.

It will be appreciated that the surgical instrument of the presentinvention has a wide variety of uses. As the tips are applied to a pieceof tissue, the surgical instrument is aligned with respect to the tissueso as to extend across the area to be sealed and/or cut. The activesurfaces will typically firmly engage the tissue and then the physicianwill activate the thermally active elements to cut and/or seal thetissue. It will be appreciated that the cutting could be done first, orthe sealing can be done first, depending on the particular desires ofthe physician. Alternatively, a surgical instrument could be made inaccordance with the present invention that operates with programmedorder, such as sealing for a given amount of time and then cutting thetissue without the physician having to activate each step.

It will also be appreciated that respective elements can be heated toseal and/or cut the tissue. While it is preferred that the activesurfaces be parallel and very close to one another, it will beappreciated that such is not necessary in accordance with the principlesof the present invention.

There is thus disclosed an improved tissue cutting and sealinginstrument. It will be appreciated that numerous changes may be made tothe present invention without departing from the scope of the claims.

1. A surgical instrument comprising: a first surface; a second surfacemovable into a position adjacent the first surface; and a thermallyactive element coupled to one of the first surface and the secondsurface, the thermally active element configured to be connectable to anelectrical power source in a closed circuit, the thermally activeelement comprising a conductor and a ferromagnetic material disposedabout the conductor such that electrical power passing through theconductor causes the ferromagnetic material to heat; wherein heat isgenerated in the thermally active element and conducted from thethermally active element to tissue to thereby treat the tissue.
 2. Thesurgical instrument of claim 1, wherein the thermally active elementfurther comprises an outer active element and an inner active element,the inner active element substantially contained within the perimeter ofthe outer active element.
 3. The surgical instrument of claim 1, whereinthe outer active element and the inner active element each form a loopand are generally parallel to one another.
 4. The surgical instrument ofclaim 1, wherein the ferromagnetic coating disposed about the conductorforms a ferromagnetic heating region along a portion of the conductor.5. The surgical instrument of claim 4, wherein the ferromagnetic coatinghas a thickness of less than about 5 skin depths.
 6. The surgicalinstrument of claim 1, further comprising a power supply and a controlfor applying a first power setting to the thermally active element toheat the thermally active element to a temperature sufficient to sealtissue.
 7. The surgical instrument of claim 6, wherein the power supplyhas a control for applying a second power setting to the thermallyactive element to heat the thermally active element to a temperaturewhich cuts tissue.
 8. The surgical instrument of claim 1, furthercomprising a power supply, and wherein the thermally active elementcomprises a first sub-element connected to the power supply so as toheat the first sub-element to a temperature which seals tissue and asecond sub-element connected to the power supply so as to heat thesecond sub-element to a temperature which cuts tissue.
 9. The surgicalinstrument of claim 1, further comprising a second thermally activeelement coupled to one of the first surface and the second surface. 10.The surgical instrument of claim 1, wherein the first surface comprisesa rigid loop.
 11. The surgical instrument of claim 1, wherein thethermally active element comprises a generally flat conductor having aferromagnetic coating disposed thereon to form an active element havinga generally planar surface.
 12. The surgical instrument of claim 11,wherein the generally planar surface is disposed on one of the firstsurface and the second surface and further comprising a cutting zoneextending away from the generally planar surface and toward the othersurface.
 13. The surgical instrument of claim 1, wherein the firstsurface and the second surface are coupled to each other via a parallelmovement linkage.
 14. A method of treating tissue, the methodcomprising: selecting an instrument having a first surface and a secondsurface movable into a position adjacent the first surface; and athermally active element coupled to one of the first surface and secondsurface, the thermally active element comprising a conductor and aferromagnetic coating disposed about a portion of the conductor; placingtissue between the first and second surface; delivering electricalenergy to the thermally active element to heat the ferromagnetic coatingand generate sufficient heat in the thermally active element to sealtissue; and delivering electrical energy to the thermally active elementto generate sufficient heat in the thermally active element to cuttissue.
 15. The method of claim 14, wherein delivering electrical energyto the thermally active element comprises connecting the thermallyactive element to a power source in a closed circuit.
 16. The method ofclaim 15, wherein the thermally active element comprises a conductor forreceiving electrical energy from the power source and a ferromagneticcoating covering at least a portion of the conductor forming a tissuetreatment region, wherein delivering electrical energy to the conductorcauses ferromagnetic heating in the ferromagnetic coating.
 17. Themethod of claim 16, wherein delivering electrical energy to theconductor cause substantially uniform ferromagnetic heating of thetissue treatment region.
 18. A tissue sealing instrument comprising: afirst arm having a first surface; a second arm having a second surfacesubstantially parallel to the first surface; and a thermally activeelement associated with one of the first and second surfaces, thethermally active element comprising a at least one conductor configuredfor receiving electrical energy from a power supply in a closed circuitand at least one ferromagnetic coating disposed along a section of theconductor; wherein the at least one ferromagnetic coating has athickness, the thickness corresponding to at least about 4 skin depths.19. The tissue sealing instrument according to claim 18, wherein thethermally active element comprises an outer active element configured tobe heated to a first temperature and an inner active element configuredto be heated to a second temperature higher than the first temperature.20. The tissue sealing instrument according to claim 18, wherein theconductor comprises a flat section and the ferromagnetic material isdisposed about the conductor at the flat section to form a generallyplanar ferromagnetic heating region.
 21. A tissue sealing instrumentcomprising: a first arm having a first surface; a second arm having asecond surface oriented generally opposite to the first surface; and athermally active element mechanism associated with at least one of thefirst surface and second surface, the thermally active element mechanismcomprising a first portion defining a sealing zone configured to heat toa temperature to seal tissue and a second portion defining a cuttingzone configured to heat to a temperature to cut tissue.
 22. The tissuesealing instrument of claim 21, further comprising a power source forproviding electrical current to the thermally active element mechanism.23. The tissue sealing instrument of claim 21, wherein the first portionand the second portion are independent thermally active elements. 24.The tissue sealing instrument of claim 21, wherein the first portion andthe second portion are sub-elements of a single thermally activeelement.